A major premise of this proposal is that RNAs present in biofluids represent a window into various cellular processes that exist in multiple tissues that release such RNAs. We have found that oncogenic KRAS mutations that occur in colorectal cancer can regulate miRNAs, mRNAs and long RNAs secreted from tumor cells in exosomes. This project (project 1) will determine what the mechanisms are by which these RNAs (cRNAs) enter the bloodstream using in vivo models and how these RNAs change with oncogenic mutations. This project will result in the creation of new tools to visualize and analyze such RNAs in real time and from blood samples in mouse models. We propose the following aims to address these questions.